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Aerial measurements in Finland

Abstract

Aerial measurements were performed to determine the {sup 137}Cs soil contamination in a given region to detect unknown radiation sources and to assess their activity. For these measurements a computerized gamma ray spectrometer, equipped with a high purity Ge-semiconductor detector and a 12 l volume Nal(Tl)-detector was used. HPGe-detector measurements from different altitudes over area I were done to test and re-calibrate the aerial measuring system. The known {sup 137}Cs contamination of (50.7 {+-} 5.2) kBq m{sup -2} could be confirmed by the measured value of (57 {+-} 10) kBq m{sup -2}. the Nal(Tl)-detector was re-calibrated at that site for further {sup 137}Cs measurements over area II. The area II was surveyed from an altitude of about 70 m and at a parallel line distance of 150 m at an flying speed of 100 km h{sup -1} to determine the {sup 137}Cs soil contamination. The measuring time was two seconds for the Nal(Tl)-detector. For the spectra measured with the HPGe-detector, a measuring time of 30 s each was chosen. From the Nal(Tl)-measurements, a mean {sup 137}Cs value of (60 {+-} 20) kBq m{sup -2} was determined with a maximum value of 90 kBq m{sup -2}. The corresponding values measured by  More>>
Authors:
Winkelmann, I; Thomas, M; Buchroeder, H; Brummer, C; [1]  Carloff, G [2] 
  1. Federal Office for Radiation Protection, Berlin (Germany)
  2. German Federal Border Police, Grenzschutz-Fliegergruppe, Sankt Augustin (Germany)
Publication Date:
Dec 31, 1997
Product Type:
Technical Report
Report Number:
NEI-DK-3090
Reference Number:
SCA: 540230; PA: AIX-29:015525; EDB-98:053937; SN: 98001946364
Resource Relation:
Other Information: PBD: 1997; Related Information: Is Part Of RESUME 95. Rapid environmental surveying using mobile equipment; PB: 440 p.
Subject:
54 ENVIRONMENTAL SCIENCES; AERIAL MONITORING; COMPARATIVE EVALUATIONS; FIELD TESTS; FINLAND; GAMMA SPECTRA; RADIATION DETECTION; SIMULATION; SOILS; SURFACE CONTAMINATION
OSTI ID:
587808
Research Organizations:
Nordisk Kernesikkerhedsforskning, Roskilde (Denmark).
Country of Origin:
Denmark
Language:
English
Other Identifying Numbers:
Other: ON: DE98616927; CNN: Contract NKS-EKO-3; ISBN 87-7893-014-6; TRN: DK9800039015525
Availability:
INIS; OSTI as DE98616927
Submitting Site:
DKN
Size:
pp. 195-204
Announcement Date:
Jun 01, 1998

Citation Formats

Winkelmann, I, Thomas, M, Buchroeder, H, Brummer, C, and Carloff, G. Aerial measurements in Finland. Denmark: N. p., 1997. Web.
Winkelmann, I, Thomas, M, Buchroeder, H, Brummer, C, & Carloff, G. Aerial measurements in Finland. Denmark.
Winkelmann, I, Thomas, M, Buchroeder, H, Brummer, C, and Carloff, G. 1997. "Aerial measurements in Finland." Denmark.
@misc{etde_587808,
title = {Aerial measurements in Finland}
author = {Winkelmann, I, Thomas, M, Buchroeder, H, Brummer, C, and Carloff, G}
abstractNote = {Aerial measurements were performed to determine the {sup 137}Cs soil contamination in a given region to detect unknown radiation sources and to assess their activity. For these measurements a computerized gamma ray spectrometer, equipped with a high purity Ge-semiconductor detector and a 12 l volume Nal(Tl)-detector was used. HPGe-detector measurements from different altitudes over area I were done to test and re-calibrate the aerial measuring system. The known {sup 137}Cs contamination of (50.7 {+-} 5.2) kBq m{sup -2} could be confirmed by the measured value of (57 {+-} 10) kBq m{sup -2}. the Nal(Tl)-detector was re-calibrated at that site for further {sup 137}Cs measurements over area II. The area II was surveyed from an altitude of about 70 m and at a parallel line distance of 150 m at an flying speed of 100 km h{sup -1} to determine the {sup 137}Cs soil contamination. The measuring time was two seconds for the Nal(Tl)-detector. For the spectra measured with the HPGe-detector, a measuring time of 30 s each was chosen. From the Nal(Tl)-measurements, a mean {sup 137}Cs value of (60 {+-} 20) kBq m{sup -2} was determined with a maximum value of 90 kBq m{sup -2}. The corresponding values measured by HPGe-detector were (70 {+-} 20) kBq m{sup -2} and 120 kBq m{sup -2}, respectively. For the evaluation of the HPGe-spectra a depth distribution parameter {alpha}/{rho} = (0.44 {+-} 0.21) cm{sup 2} g{sup -1} for {sup 137}Cs was used measured from soil samples. From data measured with the Nal(Tl)-detector during flights over area III, three{sup 60}Co-sources and one {sup 137}Cs source could be detected, localized and their activity assessed. By HPGe-detector measurements, only scattered {sup 192}lr radiation was registered. (au).}
place = {Denmark}
year = {1997}
month = {Dec}
}